Quantum Science Audio Thread

I was ready to chuck my EAR 864 (owned since 2006) because it had a forward sound and flat sound/minimal depth, kept as a back-up pre-amp.  I needed it after my pre-amp tube failed (broken voltage regulator blew and was open) and was at the repair shop.  I tried the EAR 864 again in 2023 and found it sounded better than back then.  The problem was inconsistent results, with some recordings sounding great and others mediocre or even bad.  I replaced the fuse with a Synergistic Research Blue fuse.  Immediately, it made all recordings that sounded bad or mediocre sound like it did with my main pre-amp.  After leaving it on for 60-70 hours, it settled (first it was a little dark, then too bright by 15-20 hours, then I just left it alone).  Unbelievable.  This is an excellent pre-amp (also with high end cabling, superior line tubes, phono tube, Stillpoint Ultra SS footers, etc).  Great sounding.  Without the fuse change, it was unacceptable to me (not to the designer Paravacini who distained cables, fuses and other tweaks).  His design was genius, execution could be improved. 

@macdude

Did you give the purple fuse the needed 100-200 hours of burn in time before returning. I found they sound much better after just 24 hours and improve over the next 100 or so hours.

@grannyring Yes, I did let the Purple fuse burn in. I've been happily running Beeswax fuse for a while now. I tried the stock fuse again and it was big step down from Beeswax.

Thanks. Which AM Beeswax? I think they offer 2-3 price levels? 

@grannyring I have the Ultimate Premier. It was the only fuse I tried that didn’t sound hollow. It has a depth, or roundness to it.